Combination lock



Dec. 1131., 1934. e. PRINA COMBINATION LOCK Filed Jan. 3, 1934 IIIL 41Patented Dec. 11, 1934 PATENT OFFICE COMBINATION LOCK Giuseppe Prina,Turin, Italy Application January. 3, 1934,. Serial No. 705,066

InItaly' January 4, 1933 2- Claims. (01. 70-53) Thisinvention relates toacombina-tionlock of the" type in which-thelo'cking'deviceifor the boltconsists of a plurality of combination wheels, which, when'they arebrought by--means-of pre- 2 determined angular displacements to acertain position, allow thebolt to-beoperated, while in all theotherpositions they can-possibly assume, the bolt remains locked in theclosed position.

The object of this invention is to improve the combinationlocks of theabove mentioned type, in

order to increase their safety against" picking and at the same time tomake them simpleandcheap in' construction.

According to this invention the-boltis locked in theclosed position bymeans of anumber of pawls corresponding to the number of combinationwheels and adapted to engage in a notch formed onthe bolt. Each ofthesepawlscan' be brought to the released position by means of" a camcarriedby the associated combination wheel.

The-cams of the combination wheels-are-angu-- larly displaced tooneanother, and to bring theminto engagement with the correspondingpawls, itis therefore necessaryto rotate-the-combination wheels throughdifferent angles which may be chosen at will.

The combination wheels are enclosed in the lock case and'their rotationis effect'edfror'n the outside by means'of'a sleeve mounted'capable ofrotation and axialdisplacementon a pin carrying at one end the boltactuating lever and at its other end the operating handle. The sleeve isprovided at its inner end with a dowel which can bebroughtiintoengagement with one of a plurality of notches formed at theedge of the central hole of the wheels, so that by axially displacingthe sleeve its dowel can be caused to engage the notch of the successivewheels to rotate the latter through the desired angle in order todisengage the associated lock pawl from the bolt.

To effect the desired angular displacement of the individual Wheels aspring-controlled indicating pawl is provided for each wheel, thisindicating pawl co-operating with notches formed at the rim of thewheel. The rotation of the latter should be brought in order to effectthe-rotation through the predetermined angle (a different angle for eachwheel) to bring the wheels to the released position. b

The position of the cams on the wheels may be'varied at will, therebyvarying the combina-- tion to-permit opening of the look.

A pusher provided on the inner side of the door permits all the lockpawls to be lifted and'the bolt to-be released, independently of thecombi-- nation mechanism.

The" accompanying'drawing shows by way of example a construction of theobject of this'invention.

Figure 1 shows the lock seen from the inside;

Figure 2'shows on an enlarged scale the combination mechanism in frontview and-Figure 3 isa partial side view thereof.

Figure 4 is an axial vertical section thereof;

The lock- (Fig. 1) consists of a bolt 1 moving in straps or supports 2on the case P fastened to the door, and engaging in the strap 3 oftheplate T fastened to the door frame. The bolt ismovedi from theoutside by means of a lever 4-5-keyed to the pin 6 of the outer handle 7(Fig; 4) and from the inside by means of the handle 8. The lever 4-5engages by its end in a socket Q-made of three parts (for simplicity ofconstruction) screwed to the bolt 1 and serving also as stopagainstthestraps 2 in the known manner. The bolt 1 is locked in its closedposition by lock pawls 10 engaging a notch 1' therein, (Fig. 2)fromwhich pawls it is released, from the inside, by the spring pusher 11carried by the plateP and, from the outside, by means of a combination"mechanism enclosed in a case formed by two plates 12 connected bydistance pieces 13. The pin 6 of the outer handle '7 supports thetubular pin 14 (Fig. 4) operable by means of the knob 15 by rotation onthe pin 6. The sleeve 14 carries at its end a dowel 16 movable in alongitudinal slit of the distance tube 17 and engaging in one of theradial notches 18 of the combination wheels 18. Each of these carriersalso for each internal notch 18' an outer notch 18" receiving the springcontrolled pawl 19. The sense of rotation of the wheel in which the boltis released, obtained by means of the sleeve 14, is denoted by thearrow: the number of snaps of the indicating pawl 19 into the notches 18indicates the position of the wheel 18 with reference to a determinedstarting position by rotating the wheel in the opposite direction, untilits tooth 18" engages the tooth 19 of the indicating pawl 19. Each wheel18 has a circular shoulder 18a and a cam 20 on which an arm 10a of abell crank lever rests under the pressure of a spring, the other arm ofthe lever being the pawl 10 which locks the bolt 1. When the cam 20 isunderneath the arm 10a, which is indicated by the number of snaps of theindicating pawl 19, the bolt is released from the lock pawl 10. Asear-spring 21 serves both for the indicating pawl 19 and the lever1010a.

As each wheel 18 has its associated pawl 19 and its lever l10a, therotational movement for fully releasing the bolt 1 must be repeated foreach wheel (three in Fig. 3) counting for each wheel the respectivenumber of snaps and bringing each time the dowel 16 of the sleeve 14into engagement with the wheel to be rotated.

Only when all the lock pawls 10 have been lifted, the bolt can be movedby the lever 4-5 operated by means of the handle '7 of the pin 6.Supposing the code is the number 452, and that figure 4 relates to theinnermost wheel, 5 to the intermediate wheel and 2 to the wheel nearestthe plate P, the knob 15 fully pushed-in is rotated in a directionopposite that of the rotation releasing the bolt until it is stopped,whereupon it is rotated forwardly causing the first indicating pawl 19to snap four times on the first wheel 18. This brings the first cam 20under the arm a of the first bell crank lever releasing the bolt fromthe first lock pawl 10. The knob is then displaced longitudinally to areference mark which denotes the engagement of the dowel 16 with thesecond wheel 18, for which the process is repeated. The knob 15 is thenpulled fully out and the operation is performed for the third wheel,whereby the bolt is released from all the lock pawls 10.

The bolt can be released from the inside by pressing the spring pusher11 which lifts all the lock pawls (Fig. 2). The earns 20 are screwed tothe wheels 18 and by disassembling the mechanism it is possible todisplace the cams, for which purpose holes are provided on each notch 18of the wheel thus changing the individual figure of each wheel.

Any attempt to rotate the pin 6 by means of its handle 7 is detected byan electrical indicator. The lever 4:-5 is made of two parts (Fig. l) ofwhich the part 4 is keyed to the pin 6 and the part 5 is articulated at22 to the former, the oscillation of the part 5 being limited by theengagement of the pin 4' of the part 4 in the slit 5 of the part 5. Thespring 23 tends to keep the two parts in alignment. When the part 4 isrocked by the rotation of the pin 6 (handle 7) it operates by its endremote from the part 5 and through an insulated extension a springswitch carried by the block 24. At each attempt of rotating the handle 7the toggle 45 closes slightly and the switch closes a signallingcircuit. A further rotation moves the bolt 1, owing to the engagement4--5 between the two toggle elements, only when this is admitted of bythe proper combination of the discs 18.

The action of the combination mechanism can be annulled by locking thepusher 11 by means of a suitable device, e. g. of the bayonet type inthe free position.

What I claim is:

1. A combination lock, comprising a bolt, 2. plurality of spring-pressedpawls for locking said bolt in its closed position, a plurality of cams,one for each pawl, adapted to release the latter from the bolt, aplurality of wheels on each of which is fixed in an adjustable angularposition one of said cams, said wheels being provided at the rim withnotches, a spring-pressed indicating pawl which snapping into saidnotches during the rotation of the wheel, indicates the degree ofrotation of the wheel, a pin for operating said bolt, a tubular memberrotatably mounted and axially displaceable on said operating pin and adowel fixed to said tubular member and adapted to be engaged by notchescut on the periphery of the central hole of each wheel for carrying thelatter along in rotation to release the corresponding pawl from thebolt.

2. A combination lock, comprising a bolt, a pin, a lever fixed to saidpin and engaging in a notch on said bolt for operating the latter, aplurality of spring-pressed pawls for locking said bolt in the closedposition, a plurality of cams, one for each pawl, adapted to release thelatter from the belt,

a plurality of wheels loosely mounted on said pin,

on each of which is fixed in an adjustable angular position one of saidcams, said wheels being provided at their rim with retaining notches, anindicating pawl for each wheel which by snapping into said notchesduring the rotation of the wheel indi cates the degree of said rotation,a sear-spring for each indicating pawl serving also to maintain thelocking pawl in the locked position, a tubular member rotatably mountedand axially displaceable on said pin and a dowel fixed to said tubularmember and adapted to be engaged by notches cut at the edge of thecentral hole of each wheel for carrying along the latter in rotation torelease the corresponding pawl from the bolt.

GIUSEPPE PRINA.

